Swimming has always been an enjoyable water activity for many people. Snorkeling and scuba diving in particular are water activities which are very popular with a small but increasing number of enthusiasts. Swim fins are a necessary part of the equipment needed to fully enjoy the activities. It is a well known fact that swim fins on the swimmer increases the swimmer's water speed and ability to tread water.
Significant developmental effort has been expended on swim fins in recent years. The efforts have evolved into two basic fin styles. One fin style is variously referred to as an open heel or strap fin. It has a propulsion blade portion with a partial foot pocket which fits over a front part of the foot. The fin is held on the foot with a heel strap. The heel strap is adjustable and one fin can be made to fit most sizes of feet. The second fin style is a full foot pocket or shoe fin. It is a one piece integral unit having a propulsion blade portion and a full foot pocket. The foot pocket is sized according to the individual user.
The two fin styles have their advantages and disadvantages. The open heel swim fin is made in three basic sizes. Any adjusting needed to accommodate different size feet is done by the user simply by adjusting the length of the heel strap. It also is very accommodating to protective booties which many swimmers like to wear to protect the feet against abrasions and cold temperatures. However, a secure fit is needed to retain the fin to the foot. Also, the secure fit is needed to prevent a rubbing action of the heel strap onto the foot which likely will result in painful blisters. Over tightening the heel strap is uncomfortable to the user. The conventional heel strap also exerts pressure on the user's achilles tendon which is ultimately felt over time. The bootie which is often worn provides very little protection for the back of the user's ankle against the heel strap pressure. The full foot pocket fin provides a snug secure fin when properly fitted. It is also generally accepted that the full foot pocket fin is capable of delivering more propulsion through the water. However, many sizes must be made and stocked given the many sizes of feet of the users.
As with most products, increasing popularity of swim fin use has resulted in the manufacturers increasing their development efforts to maintain or increase their market share. The propulsion blade portion itself on both styles of swim fins has received considerable attention. It has been contoured and shaped to enhance its water performance. This includes various webbing spaces, water channels and the like. Different materials of construction with varying rigidities and elasticities have also been used to enhance performance.
There also has been some effort expended to make swim fins easier to wear, though such efforts appear to be minimal. In particular, some development work has been done on heel straps which are said to be easier to use and/or more securely hold the fin to the foot. For example, see U.S. Pat. Nos. 5,083,954 and 5,868,592. In accord with a need, an improved heel strap has been developed. The heel strap solves many of the problems associated with known straps, including secure fit, comfort and ankle/foot movement maneuverability.